Micromotion and fretting damages at the dental implant/bone interface are neglected for the limitation of check methods, but it is particularly important for the initial success of osseointegration and the life time of dental implant. This review article describes the scientific documentation of micromotion and fretting damages on the dental implant/bone interface. The fretting amplitude is less than 30 l^m in vitroand the damage in the interface is acceptable. While in vivo, the micromotion＇s effect is the combination of damage in tissue level and the real biological reaction.
使用新型扭动摩擦磨损试验机,在林格溶液（Ringer’s solution）条件下,对牛髋关节软骨/Φ28 mm Al2O3摩擦副进行了扭动角位移幅值为0.5°~10°和法向载荷为5~50 N的扭动摩擦磨损试验。在摩擦动力学行为分析的基础上,使用扫描电镜（SEM）、苏木素-伊红（HE）染色法对磨痕进行了观察,分析了软骨的磨损机理。结果表明,牛髋关节软骨在扭动磨擦条件下存在2种T-θ曲线,即椭圆和平行四边形,分别对应扭动摩擦的部分滑移和完全滑移状态。在扭动摩擦处于部分滑移状态时,牛髋关节软骨表面损伤轻微,主要损伤机理为表面褶皱。处于滑移状态时,沿半径方向,磨痕可依次分为粘着区、褶皱区、微裂纹区和剥落区,其主要损伤机制为表面裂纹与剥落。
‘Bronze teeth＇ reflect the mechanical properties of natural teeth to a certain extent. Their mechanical properties resemble those of a tough metal, and the gradient of these properties lies in the direction from outside to inside. These attributes confer human teeth with effective mastication ability. Understanding the various mechanical properties of human teeth and dental materials is the basis for the development of restorative materials. In this study, the elastic properties, dynamic mechanical properties （visco-elasticity） and fracture mechanical properties of enamel and dentin were reviewed to provide a more thorough understanding of the mechanical properties of human teeth.
